Field of Invention
The invention relates to a crank mechanism for lift-slide covers disposed in the ceiling of motor vehicles.
Lift-slide covers disposed in the ceiling of motor vehicles are as a rule operated with hand cranks. It should therein be possible to carry out at least two functions with these hand cranks: the lifting of the cover about a given angle relative to an axis extending parallel to the to the ceiling of the motor vehicle as well as the sliding of the cover parallel to the motor vehicle cover. After completion of the particular function the hand crank often is in addition to be foldable into a sunken recess so that the interior side of the cover of the motor vehicle has no protruding edges. This folding-in moreover should, in addition, also be possible from each final position of the hand crank which means an additional difficulty because the crank arm can often only be folded into the sunken recess if it is in a particular position. Whether the lift-slide cover is to be lifted or slid with the hand crank can for example be decided by reversal of the direction of rotation. The cranking in the clockwise direction causes therein for example the lifting of the cover while the cranking in the counterclockwise direction effects the sliding of the cover. It is of importance in this case that a zero position between both directions of rotation is defined.
A crank drive for lift-slide roofs of motor vehicles is already known in which a crank arm is swivelled about its swivel axis into a particular position and its end extended beyond the swivel axis comes into contact with a hook at the lower end of the pin whereby this pin is pulled in the downward direction against the effect of a spring (DE-OS 24 26 765). Through the motion of the pin an outer toothing is brought out of engagement with an inner toothing at a drive pinion so that the crank arm together with a sleeve and the pin is rotatable into a position from which it can be swivelled into a sunken recess. Through the swivelling of the crank arm it is consequently no longer possible to swivel the lift-slide roof. However, in the case of this known crank drive it is of disadvantage that the crank arm before the swivel motion must first be brought from its operation position into a position which is directed counter to the later swivel motion.
Hereby the crank arm assumes three quasi-stable positions which with respect to its operation is awkward.
A similar manually operated crank and drive mechanism for a lift-slide cover with which it is possible to fold the crank arm with a multiplicity of positions of displacement of the cover into a sunken recess is known from DE-P 24 42 7190. Herein all functions for the actuation of the slide cover, specifically the sliding as well as also the setting as well as also the releasing of the latching in the closure position for enabling the setting motion can be carried out with a single actuation member specifically the crank arm. It is herein of disadvantage that the crank arm must be latched in three different positions. A first position is required when lifting the cover, a second during normal sliding of the cover, and a third in the folded-in position.
Further, a device is known for limiting the number of rotations of a shaft for rotatable drives of sliding roof drives in motor vehicles in which for two different motion progressions which can be brought about with the same shaft for optional sliding or setting when swivelling in the slide cover in spite of the setting paths which are of different length for the two motions and which are to be limited by means of the device only one shift position is provided to simplify the operation of the slide roof equipped with two shift functions (DE-P 23 33 666). Herein is slidably disposed parallel to the shaft a locking pin which permits in its shifted-in final position both directions of rotation of the drive and in its disengaged position blocks the drive in both directions. Herein is of disadvantage that the hand crank first must be brought out of its resting position with thumb and index finger. Subsequently either a second hand or the thumb of the first hand must be used for depressing a push button. Therein the index finger alone must initiate the rotation of the hand crank before it is possible to continue rotating with thumb and index finger. This is unsatisfactory from the aspect of ease of operation and safety. In the final positions the hand crank is in an oblique position and cannot be folded in. Moreover, the final stroke in the final position is not defined.
Furthermore, a slide roof is known in which a crank gear mechanism is locked in the zero position of a slide cover, thus in the closure position, through a stud engaging a disk of the crank gear mechanism which is disengaged by a dog [plate] of at least one predetermined folding position of the crank (DE-A-3 200 289). Since the locking pin is driven via a gear reduction and does not directly position the crank, and because furthermore the crank is disengaged from the gear mechanism, it is not possible to again fold in immediately the blocked crank which is again just located over the cavity.
Lastly, a hand crank apparatus for slide or lift roofs is also known with which it is possible to dispense with the actuation of a push button for latching of a once-set positioning-out height of the slide-lift roof (DE-OS 33 08 823). In this hand crank drive form-fitting engagement means are coaxially assigned to a hand crank and an input toothed wheel of a gear mechanism wherein these engagement means can be temporarily brought out of engagement against a spring load. As form-fitting engagement means are provided projections and depressions in a raster-head and a raster-plate lying one above the other. Of disadvantage in this known hand crank drive is, however, that the hand crank must be rotated and simultaneously together with a hub must be pressed upward by a particular displacement path against the load of a plate spring.